In today's scenario, most of the OEMs use manual transmissions with synchronizer gear shifting system for ease of gear shifting. It gives very high fuel efficiency. Gear shifting is a customer touch point, hence it is very important to select adequate synchronizer capacity so that it will perform in better and last longer. To test the synchronizers, there are many test methods which give the idea about life of synchronizer and its performance, in different conditions. Regular synchronizer rig tests consume lot of time in deriving the results. So it is very important to find out a way which will give same results within short time period.To carry out the short time test or accelerated test, we need to understand the effect of various factors like reflected inertia, drag torque, differential speed, synchronizing time, and gear shifting force on synchronizer capacity. After understanding the effect of various factors on synchronizer, test method is developed to carry the test which will give us the same test results as of normal traditional rig test. From above study, it was observed that reflected inertia at synchronizer and differential speed plays major roles in performance of synchronizer.In this document it is explained in detail that how all parameters behave and their effect on synchronizer system and its individual contribution for gear shift efforts. For deriving this test method, actual measurements were conducted to study the effect of above mentioned parameters. With help of simulation, new test method was derived and utilized for actual testing of double cone synchronizer in manual transmission. All above exercises finally resulted in to the new test method which reduced time for synchronizer testing and gave idea about synchronizer capacity, at initial phase of product development. It also saves the time and money with adequate test results.